title: The in vitro and in vivo behaviour of retinal pigment epithelial cells cultured on ultrathin collagen membranes.
abstract: The transplantation of pigment epithelial cells as a therapeutic modality for retinal degeneration requires that the transplanted cells form a monolayer in the subretinal space that will establish communication with photoreceptors. Since previous studies have shown that transplanted cells in suspension do not form a monolayer, it will be necessary to transplant preformed pigment epithelial cell monolayers at the location of the exposed photoreceptors. To establish cell monolayers, retinal pigment epithelial (RPE) cells were cultured on ultrathin collagen membranes. Cells were examined for morphology, for characteristics of differentiation and viability. Membrane degradation and long-term biocompatibility in vivo were assessed following subconjunctival and subretinal implantation in rabbits. These studies have shown that RPE cells adhere, proliferate, form monolayers, and acquire differentiated properties on a collagen membrane that has features similar to Bruch's membrane. Membranes transplanted subconjunctivally and subretinally exhibit excellent biocompatibility without any evidence of inflammation or rejection. RPE cells cultured on collagen membranes acquire differentiated characteristics similar to those of RPE cells in vivo and form complete monolayers that are amenable to be transplanted to the subretinal space. The collagen membranes are non-toxic and do not elicit any rejection or inflammatory response when implanted subconjunctivally or subretinally in rabbits.
authors.affiliation: Department of Ophthalmology, RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany. gthumann@ukaachen.de
authors.forename: Gabriele
authors.initials: G
authors.lastname: Thumann
authors.forename: Anja
authors.initials: A
authors.lastname: Viethen
authors.forename: Andrea
authors.initials: A
authors.lastname: Gaebler
authors.forename: Peter
authors.initials: P
authors.lastname: Walter
authors.forename: Stefanie
authors.initials: S
authors.lastname: Kaempf
authors.forename: Sandra
authors.initials: S
authors.lastname: Johnen
authors.forename: Anna Katharina
authors.initials: AK
authors.lastname: Salz
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism* / Q000648:ultrastructure; D003228:Conjunctiva / Q000378:metabolism; D005434:Flow Cytometry; D005452:Fluoresceins; D006736:Horses; D006801:Humans; D007150:Immunohistochemistry; D020007:Implants, Experimental; D008567:Membranes, Artificial; D010587:Phagocytosis; D010857:Pigment Epithelium of Eye / Q000166:cytology* / Q000637:transplantation; D019919:Prosthesis Implantation; D011817:Rabbits; D012160:Retina / Q000378:metabolism
chemical_list: D024042:Collagen Type I; D005452:Fluoresceins; D008567:Membranes, Artificial; C039083:5-((4,6-dichloro-1,3,5-triazin-2-yl)amino)fluorescein